I want to know the best mods to increase the low end on a yfz to make it more ridable when going through tight trails without having it stall. I have already done the cam mod and everything else is stock. What else can i do. Would the Dyna FS programable ignition help?

 

Increase the displacement. You can do this with a stroker crank and larger piston.

For very little money by comparison, you could change your gearing.

 

Pipe it. Make sure you buy something that was designed more for mx or trail riding. Dr.D and HMF both make good systems that add low end, but there are others. You could gear it lower also, and a heavier flywheel will definately reduce the stalling. I ride a few tight trails, and the exhaust really helped with the low end power. Couple that with a flywheel and you should be all set. The fact is, these motors are designed to rev freely, you can't really tractor it through tight spots but rather use the clutch more like you would on a 2 stroke.

 

Scooter makes some very good points.
I have the DR D, and it gives a good deal of bottom end power. Also, going down a tooth on the front end will help you out.

Additionally, I have an aftermarket cam that was designed to give a ton more bottom end, and was designed to work with the free cam mod (retarding the exhaust cam one tooth). I actually have never installed it since I ride only at the dunes and tend to wind out my motor most of the time.

Feel free to PM me if you are interested. I may just go ahead and part with it since I am probably not going to be using it any time soon. [img]i/expressions/face-icon-small-wink.gif[/img]